Automatically controlled winter air conditioning system



Feb. 11, 1941. I c BARTLETT 2,231,824

AUTOMATICALLY CONTROLLED WINTER AIR CONDITIONING SYSTEM I Filed Jun 15, 194o l I B picd/ l I 32 3! Corridor Zone l, E Duo'l a4 9 l I I Q4- v OuTdonr Air I K fan.

E/echv'c 'Sdurce .liweazi'or atented Feb. 11, 1941 AUTOMATICAILY oorrraoruzn wm'rna an; counmomo ass-rm Amos 0. Bartlett, Braintree, m, assignor to B. F. Stnrtevant Company, Boston, Mass.

Application June 15, 1940, Serial No. 340,648

, 4 Claims. (cl. see-44 This invention relates to winter air conditioning systems and relates more particularly to automatically controlled heating and humidifying systems utilizing a central air heater and 5 humidifler,1and local recirculation units.

In school buildings, for example, in the past,

- several heating and ventilating systems have been used; 'I'hehot air furnace with air circulating fan was probably first. .It was followed by the m straight blast steam system which in turn was superseded by the s-cal1ed'split system." The unit ventilator followed next and is now probably the most popular system. Unit ventilators however draw incold outdoor air at local points and 15 although they. purp rt to temper the air prior to discharge into the rooms, there is much'objection to drafts.

This invention provides a winter'air' conditioning system utilizing local recirculation units 20 of the ejector type which induce the flow or recirculated air at local points through ejector action, heated, humidified air being supplied from a central plant'under static pressure to actuate the ejector. Such units are not only'quietin gs operation, but through their use'no drafts are created for the outdoor'air is heated at the central plant before delivery to the rooms. Differing from prior so-called air'conditioning sys-' terns which were really only heating and ventiao lating systems, this invention also provides for simultaneous control of temperature, .humidity, air motion and air purity.

An object of the invention is to supply heated and humidified outdoor air to local recirculation 38 units for distribution and circulation.

Another object of the invention is to regulate.

. the temperature and humidity of air at local points and supplied from a central point.

The invention will now be described with ref- 40 erence to the drawing which is a diagrammatic view of one embodiment of the invention. The space I which maybe one of a plurality ofroomsorzonesinaschoolorotherbuilding, contains the local ejector unit I which by way 48 of example, may be'of the type disclosed generally in the U. 8. Patent No. 2,000,597 which issued May 7, 1935 on an application of R. E. Reyes, and which comprises a rectangular casing of sheet metal containing the longitudinally exl0 tendingejectornomeslandltheflnnedtube heaterlinarecirculatedairinletopeningin aside'wall oftbecasing, and theairdischarge grille I.

The central plant includes the fan II. the ggairwasheriztheinnerheaterllandtbemtsidc ,,door temperature is 34 1". or below.

- through the motor 25, the valve 20 in the steam preferred that the thermostat 24 over-ride the the hygrostat 21 will control the humidity by 40 stat is not satisfied 45 tempering heater It. The fan ii supplies the heated humidified air through the, duct it to the unit I.

In operation, the thermostat i! exposed to outdoor air adjusts-by means of the motor is, the valve l I in the steam line to the heater I4, and maintains steam in this heater when the out- During warm-up periods, the control it which maybe clock actuated, is adjusted to cause the damper motor I! to close the outdoor air damper 2i and open the recirculated air damper 20. The fan ii then draws recirculated air from the room I, through the passage 22 and duct 23, the heater I3 and washer i2 and then through the 1:; supply duct II into the unit 8, where it passes between the ejector norzlcs I and 8 and by ejector action induces the flow of room air through the localheater l. I

At the "end of the warm-up period, the control i0 isadjustedto open the outdoor air dampers 2i and to close the recirculated air dampers 20. The duct thermostat it maintains the tempera ture of the primary air in the duct ll at, for example 60 E, and .does' this 'by adjusting 21V supply line to the heater i0. The local hygrostat 3'! also-adjusts the valve II for controlling the humidity of the air delivered to the local unit. By increasing the tem- 30 perature of the air entering the washer I! by adjustment of the heater it, the relative 'humidity of the delivered air is increased. It is hygroetat 21 in control of the valve motor 25 85 when the temperature of the delivered air has reached the control temperature of 60 1". to prevent overheating cf the delivered air. Normally, the air in the duct II will be below 60 F and adjusting the temperature of the heater it. If however, the temperature in the duct l5 reaches 60 it, the thermostat 24 will act to lower the temperature of the heater It even if the-hygro- To prevent over-humidiilcation when the fan ii is not operating, the motor 20 in the circuit of the fan motor 20, its starter and the electric source 8|, closes the valve 32 in the water supply to the washer ilwhen the circuit of the i'anmotorisopen.

The local thermostat it maintains the desired localtemperature byadjustmentthroughthemotorlkotthe veil in-the'steameuwlyline to the local heater 0. a 88' The control i8 is actuated as described in the foregoing in the early morning for warm-up purposes. As illustrated, it is connected to the thermostat 2d and acts to prevent this thermostat from throttling the steam supply to the heater 83 during the warm-up period. Prior to the occupation of the building, at-the conclusion of the warm-up period, the control 58 is actuated to close the recirculated air dampers 2i] and to open the outdoor air dampers 21 whereby the air passing through the heater !3 andwasher I2 is outdoor air to supply ventilation requirements. At the same time, it renders the thermostat 24 again efiective to control the heater i3.

The nozzle 8 which may be pivoted in its lower portion at is adapted to be adjusted as by the handle 37 to vary the nozzle spacing and accordingly the ejector action. Ordinarily after preliminary adjustment for taking care of individual local requirements, the ejector is not again changed unless the local requirements are changed.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, as modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. An automatically controlled winter air conmentioned heater for adjusting the humidity of the air from said central-unit.

2. An automatically controlled winter air conditioning system comprising a central unit including a humidifier and a heater in advance with respect to air flow, 01' said humidifier, a local recirculation unit including a local heater and an ejector for inducing the flow of local air in contact with said heater, means including a duct and a fan connecting said central unit and said ejector for supplying air under pressure to said ejector,

means including a local thermostat for adjusting the temperature of said local heater, means including a local hygrostat for adjusting said first accuses mentioned heater for adjusting the humidity of the air from said central unit, and means including a thermostat in said duct for adjusting said first mentioned heater for preventing the air in said duct from exceeding a predetermined tem perature.

3. An automatically controlled winter air conditioning system comprising a central unit including a heater and a humidifier, a local recirculation unit including a local heater and an ejector for inducing the fiow of local air in contact with said heater, means including a duct and a, tan connecting said central unit and said elector for supplying air under pressure to said ejector, means including a local thermostat for adjusting the temperature of said local heater, means including a thermostat in said duct and a local hygrostat for controlling the temperature and humidity of the air from said central unit, means for alternatively supplying air recirculated from said local unit-or outdoor air through said central unit, and a control for actuating said last mentioned means to discontinue the supply of outdoor air and for rendering said duct thermostat ineffective during warm-up periods and to initiate the supply of outdoor air, to discontinue the supply of recirculated air, and to render said duct thermostat efi'ective at the conclusion of said warm-up periods.

4. An automatically controlled winter air conditioning system comprising a central unit including a humidifier and a heater in advance with respect to air flow, of said humidifier, a local mentioned heater for preventing the air in said duct from exceeding a predeterminedtemperature, means for alternatively supplying air recirculated from said local unit or outdoor air through said central unit, and a controller actuating said last mentioned means to discontinue the supply of outdoor air and for rendering said duct thermostat ineflective during warm-up periods and to initiate the supply oi outdoor air, to discontinue the supply of recirculated air, and to rendersaid duet thermo stat effective at the conclusion of said warm-up AMOS C. BARTLETT.

periods. 

